In recent years, the scope of research projects in HIV/AIDS has expanded at CWRU/UHC. The CWRU/UHC CFAR offers a mature environment for the study of HIV, not only in the U.S. but also on the international front with studies ranging from basic science to operational research. With the growth in the number and complexity of research projects and the increased sophistication of scientific questions asked, there has been a greater demand for expertise in biostatistics and epidemiology. To meet these demands, the CWRU/UHC CFAR instituted the Epidemiology & Biostatistics Core in 2001. The EpiBio Core is now tightly integrated into a larger Infectious Disease Epidemiology program at CWRU. By joining this program, the CFAR EpiBio Core integrates into a strong and well-established research program and can take advantage of economies of scale. The goal of the EpiBio Core is to assure high quality in the scientific process of AIDS research, whether descriptive or experimental, in the CFAR. The specific objectives of this core are: 1. To provide biostatistical and epidemiologic advice to CWRU/UHC CFAR investigators. 2. To provide study coordination through a Study and Data Coordinating Center at CWRU for both local and international studies conducted by CFAR investigators 3. To manage the collection and storage of data for CFAR clinical and epidemiologic studies 4. To provide training and faculty development opportunities in the area of Epidemiology and Biostatistics